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[Display omitted] • A core-shell structured piperazine pyrophosphate microcapsules (MT@PAPP) is constructed. • The MT@PAPP enhances the compatibility and mechanical property of TPE/MT@PAPP composites. • Compared with pure TPE, the PHRR and PSPR of TPE/MT@PAPP were reduced by 78.5% and 60.0%, respectively. In this study, core-shell structured piperazine pyrophosphate (PAPP) is designed to enhance the fire safety and mechanical property of styrenic thermoplastic elastomer (TPE) composites. The PAPP is microencapsulated with carbon nanotube modified melamine-formaldehyde resin to prepare core-shell structured flame retardants (MT@PAPP). Due to the excellent compatibility between the MT@PAPP and TPE matrix, the mechanical property of TPE/MT@PAPP is improved. Compared with TPE, the peak heat release rate and peak smoke production rate of TPE/MT@PAPP are decreased by 78.5% and 60.0%, respectively. Thus, the core-shell structured piperazine pyrophosphate microcapsule strategy provides an excellent approach to obtain high-performance TPE composites. [ABSTRACT FROM AUTHOR]

A synergistic flame retardant with a core-shell structure utilizes the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivative as the outer shell and ammonium polyphosphate (APP) as the inner core. Three derivatives of DOPO (DOPO-GY, DOPO-DH and DOPO-GD) are synthesized by reacting DOPO with glyoxal, paraformaldehyde and diethanolamine, and glutaraldehyde, respectively. DOPO-GY@APP, DOPO-DH@APP and DOPO-GD@APP exhibit good radical scavenging activities. The oxidation induction time for EVA/DOPO-GY@APP is exceptionally high at 19.04 min, in contrast to EVA alone, which has an induction time of only 5.51 min. Simultaneously, after aging at 180 °C and 165 °C for 7 days, the retention rates of elongation at break for EVA/DOPO-GY@APP are 34.67 % and 55.50 %, respectively. These findings demonstrate the long-term anti-aging properties of EVA/DOPO-GY@APP without the need for additional antioxidants. Moreover, EVA/DOPO-GY@APP, EVA/DOPO-DH@APP and EVA/DOPO-GD@APP all achieve V-0 rating with 25 % addition of flame retardant. In comparison to pure EVA, their peak heat release rates and maximum smoke density decrease by 52 % and 47 %, 43 % and 54 %, and 51 % and 44 %, respectively. Additionally, compared to EVA/APP, their mechanical properties have been improved. Therefore, these microencapsulated flame retardants with DOPO derivatives as the shell effectively enhance the mechanical properties and fire safety of EVA composites. [Display omitted] • A multifunctional microencapsulated flame retardant is successfully designed. • The DOPO-GY@APP shows good radical scavenging activities. • The retention rate of EB from EVA/DOPO-GY@APP can reach 55.50 % after aging at 165 °C for 7 days. • EVA/DOPO-GY@APP reveal anti-aging properties without adding any antioxidant. • The pHRR and Ds max of EVA/DOPO-GY@APP are reduced by 52 % and 47 %, respectively. [ABSTRACT FROM AUTHOR]

• The smart fabric cotaing was prepared using a one-step process. • A solid, fire-resistant gel serves as the host skeleton. • A solid–liquid switchable phase change functional guest. • The fabric effectively responds to changes in ambient temperature. The stability of personal thermal management are increasingly indispensable in modern society due to the growing demand for energy savings and environmental protection. Herein, inspired by solid–liquid host–guest materials, we propose a coating preparation strategy that uses a solid flame-retardant gel as the host skeleton filled by a solid–liquid switchable phase change flame-retardant functional guest, thus fabricating smart polyester fabrics for personal temperature management in one step. Both attenuated total reflectance (ATR) and scanning electron microscopy (SEM) are used to confirm the host–guest structure coating on the surface of polyester fabric. Results from simulated cold and heating environments show that the coated polyester fabric has a desirable personal temperature regulation ability. The skin wrapped by the coated polyester fabric presents a higher temperature compared with bare polyester fabric, in simulated cold conditions. Meanwhile, in heating conditions, the internal temperature of the coated polyester fabric is 5.2 oC lower than that of the bare polyester fabric. Furthermore, the coated polyester fabric exhibits excellent flame retardancy in the combustion test, with a horizontal burning rate of 85.7 mm/min and a peak of heat release rate (PHRR) reduction of 52.8 %, attributed to higher graphitization degree and suppressed pyrolysis products. For promoting the practical application, the water vapor transmission, washing resistance, and mechanical performance are also deeply studied. Hence, a phase-change flame-retardant polyester fabric constructed with a host–guest structure provides huge application potentials in various personal temperature management fields, such as snow rescue, field camping, and adventure activities. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multifunctional additive (MCMH) is carefully designed. • The microencapsulation technology improves the compatibility between MCMH and XLEVA. • The OIT value of XLEVA/MCMH was basically unchanged after extracted for 5 days. • The retention of EB of XLEVA/MCMH could reach 71.8% after aging at 165 °C for 14 days. • The PHRR and Ds max of XLEVA/MCMH are reduced by 89.4% and 53.6%, respectively. A multifunctional additive is carefully designed for crosslinked ethylene–vinyl acetate copolymer (XLEVA) composites to improve their mechanical properties, aging resistance and fire safety. In this study, first, a layer of silica was microencapsulated on magnesium hydroxide to give a large amount of hydroxyl group on the magnesium hydroxide surface; second, the primary antioxidant 3-(3, 5-di- tert -butyl-4 hydroxyphenyl) propionicacid was grafted on SiMH surface to prepare antioxidant microencapsulated flame retardants (MCMH). Compared with the pure XLEVA, the peak heat release rate and the maximum smoke density of flame retardant XLEVA/MCMH are decreased by 89.46% and 53.6%, respectively. Moreover, these oxidation induction time values of XLEVA/MH/AO and XLEVA/SiMH/AO decreased sharply after extracted for 1d. However, the OIT value of XLEVA/MCMH was basically unchanged after extracted for 5d. After aging at 165 °C for 14 days and γ-ray irradiation dose of 500 kGy, the retention of elongation at break could reach 71.8% and 86.6%, showing excellent aging resistance. These results show that MCMH has a good synergistic effect for enhancing the flame retardant, mechanical property as well as aging resistance of XLEVA composites. The "Killing three birds with one stone" strategy provides an excellent solution for obtaining high-performance XLEVA cable materials. [ABSTRACT FROM AUTHOR]

Due to the inherent flammability of polypropylene (PP), it is limited in the application of flame retardant materials. In this work, a novel char forming agent, hyperbranched phosphorus-containing polyurethane (HPPU), was synthesized and used as efficient char forming agent. When ammonium polyphosphate (APP) was combined with HPPU, APP/HPPU endow PP significantly improved flame retardancy than single APP. Although the total carbon monoxide production (TCOP) of some PP/APP/HPPU composites is higher than that of PP/APP composite, it is still lower than that of neat PP. LOI (limited oxygen index) and UL-94 tests reveal that PP composites with 25 wt% HPPU/APP with ratio of 4:1 are able to reach 27 vol% and V-0 rating, respectively. The addition of 25 wt% APP/HPPU with ratio of 2:1 into PP can result in decrease in peak heat release rate of about 72%, decrease in total heat release of about 38% and decrease in TCOP of about 93%. APP/HPPU promotes PP to form more stable, compact, and continuous char layer which effectively hinder heat and oxygen transfer and protect the inner matrix from decomposition. Thermogravimetric-infrared results reveal that the gas phase flame retardant mechanism of APP/HPPU is the dilution effect of ammonia from APP and the flame inhibition effect of phosphorus-containing species from HPPU. Image 1 • A novel hyperbranched phosphorus-containing polyurethane (HPPU) is firstly synthesized. • LOI and UL-94 tests revealed that the addition of 25 wt % HPPU/APP into neat PP was able to reach 27 % and V-0 rating. • APP/HPPU exhibit remarkable flame retardant and carbon monoxide (CO) suppression to PP composites. [ABSTRACT FROM AUTHOR]

• An ionic confinement engineering approach is proposed to facilitate dynamic ionic crosslinking. • The ionomers deliver low dielectric-k property, high stretchability and fast self-healing capability. • The EGaIn-infused stretchable device is designed for electronic device reconfiguration. Ionomers are gaining much attention in the fields of soft robots, flexible electronics, and artificial intelligence. However, intrinsic dynamics modulation of ionomer molecules to achieve desirable properties is highly required and challenging due to a lack of understanding of the interactions between polymerics and ionic species. In this study, a novel ionic confinement engineering approach was employed, in which the composition of a copolymer, namely, PTAE-Fe, was adjusted to facilitate dynamic ionic crosslinking, which enables high stretchability (>10000 % elongation). The proportion of ionic functional groups in PTAE-Fe significantly enhanced the self-healing efficiency up to 95 %. The ionic confinement strategy also promotes electron momentum locking, resulting in a low dielectric-k property (D k < 2.5), while a reduction in the heat release rate of 69.1 % makes the ionomer an excellent flame retardant material. In addition, a eutectic gallium-indium (EGaIn)-infused stretchable device and low D k flexible ink were designed according to the ionic confinement strategy. The as-fabricated ionomer is expected to benefit a wide range of energy and storage technologies. [ABSTRACT FROM AUTHOR]

The dispersion problems of black phosphorus (BP) in polymer-based composites can be solved by designing isolation structure. An isolating structural material with functionalized BP nanosheets and polystyrene (PS) microspheres was prepared by molding method. Firstly, the sulfonated BP nanosheets with negative charge were obtained by electrochemical diazo modification (electrochemical diazo modification of BP is first report, and achieved good synchronous stripping and modification effect). The sulfonated BP and the PS microspheres with positive charge were self-assembled to form composite microspheres through strong electrostatic interaction. The prepared composite microspheres were further hot pressed near the glass transition temperature to selectively distribute the BP nanosheets at the interface of the fused PS microspheres. Therefore, the PS-BP isolation structure with uniform dispersion and reasonable distribution was obtained in the PS matrix. Thanks to this unique structure, the maximum heat release rate and smoke production rate reduction of the isolation structure can reach 50.1% and 43.3%, which at an excellent level in the same kind of two-dimensional material based composites. The tensile strength is maximally increased by 71.7% when the filling amount is 1.0 wt%. This simple method provides a new strategy for modifying BP and is expected to be applied to the preparation of high performance polymer-based composites. [Display omitted] • An isolation structure with black phosphorus and polystyrene microspheres is achieved. • The electrochemical diazo modification of black phosphorus is the first report. • The heat release rate and smoke production rate of the isolation structure is significantly reduced. [ABSTRACT FROM AUTHOR]

The dispersion problems of black phosphorus (BP) in polymer-based composites can be solved by designing isolation structure. An isolating structural material with functionalized BP nanosheets and polystyrene (PS) microspheres was prepared by molding method. Firstly, the sulfonated BP nanosheets with negative charge were obtained by electrochemical diazo modification (electrochemical diazo modification of BP is first report, and achieved good synchronous stripping and modification effect). The sulfonated BP and the PS microspheres with positive charge were self-assembled to form composite microspheres through strong electrostatic interaction. The prepared composite microspheres were further hot pressed near the glass transition temperature to selectively distribute the BP nanosheets at the interface of the fused PS microspheres. Therefore, the PS-BP isolation structure with uniform dispersion and reasonable distribution was obtained in the PS matrix. Thanks to this unique structure, the maximum heat release rate and smoke production rate reduction of the isolation structure can reach 50.1% and 43.3%, which at an excellent level in the same kind of two-dimensional material based composites. The tensile strength is maximally increased by 71.7% when the filling amount is 1.0 wt%. This simple method provides a new strategy for modifying BP and is expected to be applied to the preparation of high performance polymer-based composites. [Display omitted] • An isolation structure with black phosphorus and polystyrene microspheres is achieved. • The electrochemical diazo modification of black phosphorus is the first report. • The heat release rate and smoke production rate of the isolation structure is significantly reduced. [ABSTRACT FROM AUTHOR]

[Display omitted] • The octopus sucker-inspired M@CN with hierarchical structure is successfully synthesized. • The Interface engineering between M@CN and TPU matrix is greatly improved. • TPU/M@CN demonstrates superior improvement of TS of 79.5% and EB of 113.5%. • The pHRR and smoke suppression of TPU/M@CN-3 are reduced by 54.1% and 40.4%, respectively. Developing high-performance polymer materials with excellent mechanical properties and fire safety in fires remains a thorny challenge. In this article, hierarchical structure MXene@carbon nanotubes (M@CN) are prepared through electrostatic interactions for enhancing the interfacial engineering of thermoplastic polyurethane (TPU). With biomimetic method, the TPU/M@CN-3 nanocomposites performed octopus sucker-inspired structure during the stretching behavior, making the tensile strength and elongation at break of TPU/M@CN-3 increase 79.5% and 113.5%, respectively. What's more, thanks to the 1D-2D hierarchical structure of M@CN, fire safety of these TPU nanocomposites were extremely reinforced. Compared with the pure TPU, the TPU/M@CN-3 of peak heat release rate (pHRR) and smoke density max (Ds max) reduced by 54.1% and 40.4%. The production rates of carbon monoxide (CO) and carbon dioxide (CO 2) were reduced by 62.7% and 33.0%, respectively. Therefore, this work provides a convenient way to prepare a high-performance TPU with highly mechanical properties and fire safety through enhacing the interfacial engineering. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photothermal of EP/SL-EBP-CoP is linearly increased (r2 > 0.994). • EP/SL-EBP-CoP 2 separately reduces PHRR, THR and PCOP by 59.88%, 39.26% and 36.41%. • Phosphorus, P-O-P and P-O-C are nodes, units and capture bonds in 3D sutured char. • Rupture molecules of char layer (C n H 2n+2 PO 4 , m / z = 168, 139 and 124) are discovered. To overcome the high flammability of polymers and endow them with photothermal capability, we fabricate the targeted nanofiller black phosphorus (BP) based SL-EBP-CoP for epoxy. Interestingly, the good ability of photothermal for EP/SL-EBP-CoP 2.0 nanocomposite changes with irradiation power can be linearly quantified (r2 > 0.94). Secondly, EP/SL-EBP-CoP 2.0 separately reduces peak heat release rate (HRR), total HRR and peak carbon monoxide (CO) production by 59.88%, 39.26% and 36.41% compared with EP, along with the lowest fire growth index. The significantly reduced hazard of heat and CO is attributed to the combined effects of 2D BP, catalysis of CoP and the structure of sutured char. Finally, the pyrolysis of BP-based flame retardants produces P 4 , P 3 and P 2 with an abundance of 77.10%, 6.75% and 14.70%. Moreover, flame retardant composites are highly dependent on the final char. This work demonstrates that phosphorus and P-O-P (PO x) are nodes and bonding units in the char, PO x bonds to the hydrocarbon fragments through P-O-C bonds. Particularly, pyrolysis molecules of suture and rupture of char (C n H 2n+2 PO 4 , m / z = 168, 139 and 124) are first discovered. This work booms the path and lays the foundations for the photothermal and fire safety of BP nanocomposites. [ABSTRACT FROM AUTHOR]

Devoting to coping with safety risk spreading with polymers, this work achieves dramatic synergistic improvements in composite toughness, photothermal healing, and fire safety through a novel targeted modification strategy for black phosphorus (BP). In detail, we herein use the emerging 2D BP as a template for in-situ growth by covalent triazine framework (HBP-CTF). Incorporating gradient increased HBP-CTF (1, 2, 4 wt%) into polystyrene (PS), the elongation at break increased by 61.59%, 74.60% and 62.82% for composites, respectively. This is attributed to the synergistic effects of two components of HBP-CTF as stress conduction unit and interface and dispersion improver, respectively. Furthermore, PS/HBP-CTF composites achieve photothermal healing over 96% in strength and elongation at break induced by outstanding photothermal properties (linearly quantifiable, R2 > 0.997). Noted, PS/HBP-CTF 2.0 and PS/HBP-CTF 4.0 achieve record reductions of 61.77% and 69.85% in peak heat release rate, accompanied by dramatically reduced total heat release. Taking the pyrolysis of HBP-CTF as an index, this work proposes the idea of using P 4 as the key product to monitor and distribute gas phase effects for BP-based flame retardants. The hybridization of CTF to HBP promotes the slow and continuous release of P 4 in the gas phase, revealing the structure and composition of char that cross-linking P and N. This work provides strategies for synergistically overcoming composite brittleness, crack failure, and high flammability, paving the way for practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Environmentally friendly new flame retardant f-HAPNW was successfully prepared. • f-HAPNW achieved high filler efficiency in reducing THR and TSP of UPR nanocomposites. • UPR/f-HAPNW 0.5 achieved an 61.2 % increase in impact strength. • Novel flame retardancy and mechanical reinforcement mechanism about f-HAPNW. Non-toxic, low-smoke, high-efficiency and environmentally friendly flame retardants have become a hot issue at present. Here, polyphosphazene crosslinked by hexachlorocyclotriphosphazene (HCCP), 3-aminopropyltriethoxysilane (APTES), and dopamine (DA) was used to modify hydroxyapatite nanowires (HAPNW), obtaining a new environmentally friendly nanohybrids (f-HAPNW). Immediately afterwards, f-HAPNW was incorporated in unsaturated polyester (UPR) matrix in the presence of a nanowire structure with a high aspect ratio, accompanied by excellent interfacial compatibility. The incorporation of a small amount of f-HAPNW achieved an overall improvement in the fire safety and mechanical properties of UPR nanocomposites, including 23% decrease in total heat release rate (THR), 25.7% and 29.5% reduction in total smoke production (TSP) and the peak of CO production rate (PCOP) when the content was 2.0 wt%; 80.1% and 11.9% simultaneous increase in tensile strength and fracture elongation, and 61.2% increase in impact strength when the content was 0.5 wt%. Compared with similar previous research, the introduction of bio-based materials and environmentally friendly flame retardants in the design achieved significant flame-retardant filler efficiency, while considering the issues of reducing smoke release and environmental pollution. In general, this work innovatively prepared an environmentally-friendly hierarchical f-HAPNW structure, and achieved a comprehensive improvement in the performance of UPR nanocomposites, providing a reference idea for the design of high-performance UPR nanocomposites. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel phosphine oxide-containing hyperbranched polyol was synthesized. • RPUF containing POCHP and EG exhibit excellent fire safety and physical properties. • The production of CO and NO x during combustion of RPUF are significantly decreased by combination of POCHP and EG. In this work, a novel phosphine oxide-containing hyperbranched polyol (POCHP) was synthesized. Then POCHP and/or expandable graphite (EG) were incorporated into rigid polyurethane foam (RPUF). EG increases foam density and deteriorates compressive strength and thermal conductivity, but POCHP has opposite effects. A 12.8% improvement of compressive strength and slightly decreased density and thermal conductivity are achieved by ERPUF50 containing POCHP and EG. And it reaches a limited oxygen index of 30.0% and UL-94 V-0 rating with immediate self-extinguishing behavior after removing flame. The peak heat release rate, total heat release and total smoke production of ERPUF50 are reduced by 71.1%, 52.2% and 71.1% respectively via bi-phase flame retardant mechanisms. Interesting phenomena were observed that POCHP promotes the intumescence of EG after combustion. The results of combustion gas analysis reveal that single POCHP or EG reduces the production of CO but increases the generation of NO x. ERPUF50 exhibits a 52% decrement of CO and an unexpected 40% diminishment of NO x. ERPUF50 with excellent comprehensive properties can not only be used as fire safe thermal insulation material with high physical performances, but also significantly reduce the release of contaminative smoke, CO and NO x in fires and waste RPUF disposal by combustion. [ABSTRACT FROM AUTHOR]

As known, the poor toughness and low fire safety of bismaleimide resin (BMI) has become a problem which restricts its further application in advanced high-performance field. Therefore, a novel allyl-functionalized linear polyphosphazene (PMAP) was designed and synthesized. With inclusion of 3wt% PMAP, the peak heat release rate (PHRR) and total smoke production (TSP) of BMI/PMAP-3 are reduced by 51.3% and 17.8%, respectively. And the residual char of BMI/PMAP increases significantly as well. Furthermore, the flame-retardant mechanism of BMI/PMAP is proposed. In condensed phase, PMAP can participate in the formation of residual char of BMI/PMAP and the char layer is with an excellent physical barrier effect by the existence of phosphorus oxygen and phosphorus nitrogen cross-linking substances. In gas phase, phosphorous oxygen free radical is also generated from PMAP, which can capture gas-phase chain free radicals and inhibit gas-phase combustion. Moreover, the impact strength of BMI/PMAP-3 increases by 85.3%, which indicates that the toughness of BMI/PMAP is effectively enhanced. The toughening mechanism of PMAP on BMI can be assigned to elastomer toughening. Therefore, with modification of PMAP, BMI/PMAP is indeed of better comprehensive performance, which is in line with expectation and provides inspiration for the simultaneous flame-retardant and toughening modification of BMI. [Display omitted] • Innovation: bifunctional allyl functionalized linear polyphosphazene was firstly synthesized. • High-efficiency: the PHRR and impact strength of BMI/PMAP-3 is reduced by 51.3% and increased by 85.3%. • Mechanism: the flame retardant and toughening mechanism is proposed. [ABSTRACT FROM AUTHOR]

• Hydrophobic hierarchical OH-BN@CuCoOx was innovatively prepared by the MOF-derived strategy. • OH-BN@CuCoOx achieved high filler efficiency in reducing THR and TSP of BMI. • BMI/OH-BN@CuCoOx 0.5 achieved an 80 % increase in impact strength. • BMI/OH-BN@CuCoOx 0.5 achieved a 49 °C increase in Tg. In this work, the MOF-derived strategy was used to generate copper-cobalt metal oxide (CuCoOx) in situ on the surface of hydroxylated boron nitride (HO-BN), and a new type of nano-hybrid (HO-BN@CuCoOx) was obtained. Then, HO-BN@CuCoOx was dispersed in the bismaleimide resin (BMI) matrix in the form of a layered structure, forming a strong interface interaction. The results of the cone calorimeter test exhibited that the fire hazard and toxic smoke release of BMI nanocomposites containing 2 wt% HO-BN@CuCoOx were effectively suppressed, such as a 37.2% reduction in total heat release rate (THR), a 38.5% reduction at peak heat release rate (PHRR), 24.3% decrease in total smoke production (TSP) and 62.2% decrease in peaks of carbon monoxide (CO) production rate. Compared with previous studies, higher filling efficiency was achieved. In addition, BMI/HO-BN@CuCoOx 0.5 achieved an 80% increase in impact strength, revealing excellent toughness. In particular, the glass transition temperature (Tg) of BMI/HO-BN@CuCoOx 0.5 reached 330 °C, an increase of 49 °C compared to the pure sample, which increased the potential for application in extreme environments. Therefore, the developed new BMI/HO-BN@CuCoOx nanocomposites expanded the application potential of BMI in the high-end field. [ABSTRACT FROM AUTHOR]

Conductive polymer composites have been caught increasing attentions in electromagnetic interference (EMI) shielding field. Due to the flammability of polymer and long-term high power working status, fire incidents on environment and human health must be taken into consideration during the preparation of the polymer materials. Thus, developing an EM waves-clean material with exceptional fire safety and smoke suppression capacity is the vital issue. In this article, a facile and eco-friendly approach to fabricate flame retardant polyurethane (PU) sponge was carried out by layer-by-layer (LBL) self-assembly with octaammonium-polyhedral oligomeric silsesquioxane (OAPOSS) and titanium carbide (Ti 3 C 2 T x) nanosheets. With the help of silicane and the barrier effect from Ti 3 C 2 T x , the peak heat release rate (pHRR) and total heat release (THR) decreased by 50%. Thanks to the exceeding catalytic capacity of Ti 3 C 2 T x nanoflakes, the production of harmful smokes or gases such as carbon oxide (CO) and carbon dioxide (CO 2) were sharply reduced with 71% and 27%, respectively. Furthermore, the flame retardant PU sponge obtained electromagnetic interference (EMI) shielding capacity after dip-coating procedure in MXene dispersion owing to the excellent electrical conductivity of Ti 3 C 2 T x nanosheets. The EMI shielding effectiveness (EMI SE) accomplished 32.57 dB and still remained 27.63 dB after 300 times compression. Therefore, this work could provide a promising way to accomplish flame retardant PU sponge with superior smoke suppression capacity, which could be used in cleaner production of modern electronics and EMI shielding materials. [Display omitted] • The facile cleaner approach to obtain multifunctional polyurethane (PU) sponge. • OAPOSS@MXene nanocoating was constructed on PU sponge via a clean layer-by-layer method. • The peak heat release rate and CO production was decreased by >50% and 71%, respectively. • Electromagnetic interference shielding capability remained >85% after 300 times compression. • Toxic fire effluents release-cleaner, electromagnetic waves-cleaner production of PU sponge were achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • 0D-2D hierarchical nanostructure was prepared via ZHS in-situ growing on Ti 3 C 2 T x. • EP-ZHS@M composites show up superior improvement of thermal conductivity of 328%. • EP-2.0 ZHS@M performed low pHRR of 54.91% and outstanding smoke suppression. • ZHS@M cut off the thermal disaster chain for safer package materials. Epoxy resin (EP) is widely used in the package of modern electronic products for thermal management, but the extremely flammability and toxicity release have restricted its further application. In this article, zinc hydroxystannate (ZHS) nanocubes were in-situ fabricated on the surface of titanium carbide (Ti 3 C 2 T x) MXene nanosheets (ZHS@M) for improving the thermal management capacity of EP. Due to the phonon thermal conductance from ZHS and electron-hole thermal conductance of Ti 3 C 2 T x , the thermal conductivity was improved by 328% compared with the neat EP, which was benefit to dissipate heat for reducing the possibility of thermal disaster chain happening. Furthermore, owing to the 0D-2D hierarchical structure of ZHS@M, the fire safety and smoke suppression of these EP composites were highly strengthened. The peak heat release rate (pHRR) and total heat release (THR) decreased by 54.91% and 58.74%, respectively. Moreover, hazardous gases of EP during the combustion were also efficiently reduced, and the generation of carbon oxide (CO) and carbon dioxide (CO 2) were decreased by 44.44% and 39.46% when the additive of ZHS@M was only 2 wt%. As a result, ternary catalytic effect and labyrinth structure improved the safety of EP in the thermal runaway incidents. Besides, EP-2.0 ZHS@M exhibited excellent tensile robustness (64.71 MPa) and modulus (2.39 GPa), which regarded as a reliable supporting material for electronics in thermal management field. Hence, this hierarchical EP-ZHS@M composites provided the help of cleaning the thermal accumulation and increasing fire safety while facing thermal runaway, which was significant to destroy the formation of thermal disaster chain and further applications of the modern electrons and devices. [ABSTRACT FROM AUTHOR]

• Hierarchical Ti 3 C 2 T X @PHbP-PHC architecture was innovatively synthesized. • Ti 3 C 2 T X @PHbP-PHC exhibited significant decrease in PHRR, THR and TSP. • BMI/Ti 3 C 2 T X @PHbP-PHC 0.5 achieved a significant increase in impact strength. • The synergistic mechanical reinforcement and flame-retardant mechanism among Ti 3 C 2 T X , PHbP and PHC was innovatively revealed. The effect of hindered amine light stabilizer on free radical quenching can be combined with the cross-linked polyphosphazene containing P N structure to improve the flame retardant efficiency of titanium carbide (Ti 3 C 2 T X) in both gas phase and condensed phase. Here, a hindered amine and polyphosphazene modified Ti 3 C 2 T X (Ti 3 C 2 T X @PHbP-PHC) was obtained. With the loading of Ti 3 C 2 T X @PHbP-PHC in the bismaleimide resin (BMI) increased to 2 wt%, an 43% reduction was achieved in the peak heat release rate (PHRR), and a 47% reduction in the total heat release rate (THR). Meanwhile, the total gaseous products and total smoke production (TSP) exhibited a similar decreasing trend. Furthermore, 0.5 wt% BMI system exhibited the highest storage modulus (2629 MPa) and impact strength (13.7 MPa), which were 21% and 76% higher than pure BMI, respectively. Therefore, the developed functionalized Ti 3 C 2 T X can be effectively used in BMI matrix, thereby providing reliable source material for the design of high-performance BMI resins that meet various application scenarios. [ABSTRACT FROM AUTHOR]

In order to enhance the fire resistance of poly(methyl methacrylate) (PMMA), a new transparent flame-retardant coating was prepared by coating hyperbranched poly(urethane-phosphine oxide) (HPUPO) onto PMMA surface, which was synthesized from 4,4′-diphenylmethane diisocyanate (MDI) and trihydroxymethylphosphine oxide (THPO). The ratio of MDI to THPO was changed to prepare HPUPO with different structures. The HPUPO coatings show a strong adhesion of 5B grade to PMMA and all coated PMMA have a high transparency as pure PMMA. In cone calorimetry test, peak heat release rate (PHRR) of all HPUPO coated PMMA decrease very obviously. The PHRR and total heat release (THR) values of PMMA-0.8 (HPUPO coated PMMA with the ratio of MDI to THPO 1: 0.8) are reduced by 83.6% and 33.0% compared to those of pure PMMA. For PMMA-1.1 and PMMA-1.25, the heat, smoke and toxic gas release are all decreased effectively, which indicates improvement of fire safety of PMMA. The PHRR, THR, total smoke production (TSP) and CO yield (COY) of PMMA-1.1 are decrease by 83.3%, 11.0%, 27.6% and 34.8%, respectively. In the back temperature test, PMMA-0.95 and PMMA-1.1 have the lowest back temperature rise rates in HPUPO coated PMMA, and the back temperature are about 200 °C under the continuous burning of the alcohol lamp for 800 s. In summary, PMMA-1.1 shows excellent transparency, adhesion and fire safety. HPUPO coated PMMA is a promising fire safe PMMA material for practical application and HPUPO can be used as transparent flame retardant coating with tailorable properties. [Display omitted] • A transparent flame retardant coating for PMMAwas prepared with hyperbranched poly(urethane-phosphine oxide). • The HPUPO coatings show a strong adhesion and high transparency. • The HPUPO coatings can effectively improve the fire safety of PMMA. [ABSTRACT FROM AUTHOR]

Nowadays, highly flexible, ultrathin, and conductive polymer composites are exceptionally desirable for electromagnetic interference shielding (EMI) applications due to their unique mechanical strength and electrical and flame-resistant properties. While the traditional nanocomposites blending remains the mainstream method to fabricate polymer/inorganic composites, it results in poor electrical conductivity caused by the discontinuous connection of conductive network as well as the unsatisfactory mechanical strength limiting the further practical applications. Herein, we introduce a facile and practical methodology involving the fabrication of self-interlocked poly (vinyl alcohol) (PVA) and conductive Ti 3 C 2 T x MXene networks, then combining them to construct a nanostructure-engineered PVA/MXene membrane. This membrane exhibits superior mechanical strength, in which the tensile strength is about three times higher than the control PVA. Additionally, the membrane demonstrates outstanding fire-resistant performances with an 80% reduction of peak heat release rate than pure PVA. More importantly, this unique membrane with random conductive networks possesses an outstanding EMI shielding efficiency near 41 dB much greater than traditional composite, which meets the requirement of high-efficiency EMI shielding applications. This article displays a novel strategy to fabricate a nanostructured polymer membrane with outstanding fire resistance, electrical conductivity, and mechanical strength, targeted and designed for high-efficiency EMI shielding applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nano-, submicron- and micron-sized Cu 2 O crystals were synthesized and confirmed. • The surface modification of Cu 2 O with PAPI improved the efficiency and dispersion. • Nano-sized Cu 2 O with the high surface area conduced to the complete combustion of RPUF. • The flame retardance and smoke toxicity suppression of Cu 2 O was explored. The development of flame retardant rigid polyurethane foam (RPUF) composites with low smoke toxicity emission, as well as excellent mechanical properties remains a huge challenge. Herein, a facile wet chemical approach was proposed for the preparation of cuprous oxide (Cu 2 O) crystals with different sizes, i.e. approximately 5 nm, 100 nm and 1 μm in lateral size, which were confirmed by X-ray diffraction and transmission electron microscopy. The effect of Cu 2 O crystals on the combustion behavior of RPUF was evaluated by cone calorimetry and steady state tube furnace tests. Significant reduction in peak carbon monoxide (CO) production rate (by 41.2%, 67.6% and 27.9%) and total smoke production (21.6%, 16.1% and 12.2%) were realized by the incorporation of 2 wt% Cu 2 O into the RPUF matrix in addition to a slight reduction in peak heat release rate. Notably, nano-sized Cu 2 O with high specific surface area is beneficial for the complete combustion of RPUF and the conversion of CO to carbon dioxide (CO 2), involving the reduction of Cu2+-Cu+-Cu0 by degraded gases and the oxidation of Cu0-Cu+-Cu2+ by oxygen. This work demonstrated that submicron-sized Cu 2 O is an effective smoke and toxic gases suppressant for RPUF, which is expected to find practical applications in polymeric materials. [ABSTRACT FROM AUTHOR]

The designing of 3D ternary-structure based on SnO 2 nanoparticles anchored hollow polypyrrole microspheres interconnected with N, S co-doped grapheme (NSG-P-SnO 2). • A 3D ternary-structure of NSG-P-SnO 2 is rationally designed. • Remarkable enhancement in polymer fire safety is achieved by adding NSG-P-SnO 2. • The flame retardancy comparison with reported work affirms the superiority of NSG-P-SnO 2. • Obviously improved mechanical performance is also observed. Inherent nature of serious fire hazard including considerable heat and toxicants releases, have definitely compromised the extensive usage of epoxy resin (EP). In this investigation, a three-dimensional (3D) ternary-structure based on SnO 2 nanoparticles anchored hollow polypyrrole microspheres interconnected with N, S co-doped graphene (NSG-P-SnO 2) is rationally designed, and further incorporated into EP matrix. The markedly suppressed fire hazard is achieved after its incorporation. By adding 3.0 wt% NSG-P-SnO 2 , the reductions on peak heat release rate and total heat release values are 42.4 and 47.8%, separately, reflecting the impeded heat generation. Meanwhile, the peak smoke production rate and total smoke production values are obviously reduced by 27.0 and 40.2%, manifesting the attenuated fire toxicity. The flame retardancy comparison with reported work demonstrates the superiority of NSG-P-SnO 2. Notably, the enhanced mechanical performance is also observed. By using 1.0 wt% NSG-P-SnO 2 , the storage modulus is remarkably elevated by 29.1%. Thus, it is concluded that, using this 3D ternary-structure can endow polymer with high fire safety and mechanical capability, synchronously. This work may provide effective inspiration towards developing multicomponent integrated architecture, optimizing their prospects in polymer-matrix composite as well as other fields. [ABSTRACT FROM AUTHOR]

• Innovation: novel g-C 3 N 4 @PPZ to promote flame retardant and toughness of BMI. • High-efficiency: PHRR and TSPR of BMI/g-C 3 N 4 @PPZ2.0 reduced by 52.1%, 53.8%. • The best impact strength of BMI/g-C 3 N 4 @PPZ increased by 184.0%. • Mechanism: the flame retardant and toughening mechanism was proposed. It's acknowledged that the inferior toughness of bismaleimide resin (BMI) is the crucial problem hindering its development and application especially in aerospace, mechanical and electronic fields. While the poor fire safety of toughened BMI is another problem urgently needed to be resolved. Therefore a novel g-C 3 N 4 @PPZ hierarchical architecture constituted of porous g-C 3 N 4 tubes modified by polyphosphazene was designed and fabricated to improve the fire safety and mechanical properties of BMI in this work. Especially compared to pure BMI, the peak heat release rate (PHRR) and peak smoke production rate (PSPR) of BMI with an incorporation of 2 wt% g-C 3 N 4 @PPZ (BMI/g-C 3 N 4 @PPZ2.0) are at 246.3 kW/m2 and 0.12 m2/s accompanying with 52.1% and 53.8% reduction respectively. The total heat release (THR) and total smoke production (TSP) of BMI/g-C 3 N 4 @PPZ2.0 are endowed with reductions of 29.4% and 42.9% as well, which demonstrates that the fire safety including heat and smoke hazards of BMI/g-C 3 N 4 @PPZ2.0 is significantly improved. With regard to the mechanical performance of BMI composites, the impact strength of BMI/g-C 3 N 4 @PPZ1.5 is 18.89 kJ/m2 which increases by 184.0% in comparison with that of pure BMI resin (6.65 kJ/m2). And it's found that the impact strength of BMI/g-C 3 N 4 @PPZ are still higher than pure BMI in hot-humid environment, which signifies that the BMI/g-C 3 N 4 @PPZ would be preferred in the industrial applications. Meantime the possible flame retardant and toughening mechanism of g-C 3 N 4 @PPZ in BMI is detailed investigated and proposed as well. [ABSTRACT FROM AUTHOR]

Similar to graphene, few-layer black phosphorus possesses many excellent properties such as good thermal stability, mechanical properties and unique characteristic dimension effects, which is considered as promising nanoadditives. But the low yield and inferior interfacial adhesion with polymer matrix are unavoidable obstruction to fabricate high performance nanocomposites. Herein, we report a facile and environmentally friendly approach to simultaneously exfoliate and modify black phosphorus (BP) by electrochemical cathodic exfoliation, where BP crystal acted as the cathode and ethylene imine polymer (PEI) acted as electrolyte and modifier. The positively charged PEI would uniformly anchor on the surface of the newly peeled-off BP nanosheets through electrostatic attraction effect, resulting in preventing the agglomeration of BP nanosheets and improve the compatibility between BP and waterborne polyurethane (WPU) matrix. Significantly, with the addition of 2.0 wt% PEI modified BP in WPU matrix, the fire safety of WPU composites was enhanced. The peak heat-release rate, total heat release, total smoke production and total CO yield are decreased by 34.3%, 21.2%, 22.3% and 50.2% compared to pure WPU, respectively. Also, the tensile strength of WPU composites was increased by 71% (from 21.9 to 31.0 MPa) at the cost of the breaking elongation slightly decreased by 5.6%. This work provides the possibility for the scalable preparation and a real application of BP in polymer nanocomposites. Image 1 • A facile and environmental route to simultaneously exfoliate and modify BP. • BP-PEI had good flame-retardant contributions in both gaseous and condensed phase. • Functionalized BP enhanced flame-retardant properties of WPU composite. [ABSTRACT FROM AUTHOR]

As is well known, polyethylene (PE) is flammable with the release of abundant heat, confirming its low fire safety. Consequently, the extended application of PE is restrained. In this work, we propose the facile preparation of multi-component hybrid (functionalized montmorillonite anchored with ZnO, defined as FMZH) and its promising utilization in PE. With the aid of functionalized compound, the obtained hybrid shows good dispersion state, as well as strong interfacial interaction with polymer matrix. By incorporating FMZH fillers, the marked reductions in peak heat release rate (PHRR) and total heat release (THR) can be obtained, corroborating the enhanced fire safety. Specifically, with the addition of 5.0 wt% 1-2FMZH and 1-4FMZH, the PHRR values are reduced to 567 and 667 kW/m2, respectively, corresponding to 54.7 and 46.8% decrease. Also, the suppressing effect on the release of decomposition fragments can be evidenced by the decreased absorbance intensity in FTIR spectra. Furthermore, the presence of these fillers shows marginal influence on the nonisothermal crystallization behavior of PE. Additionally, the FMZH composite with hierarchical structure shows superior gas barrier function over pristine ZnO and montmorillonite. • Preparation of multi-component hybrid of FMZH is proposed. • With the aid of functionalized compound, the obtained hybrid shows good dispersion. • By adding FMZH fillers, the marked reductions in peak heat release rate are obtained. • This hierarchical structure of FMZH shows more superior gas barrier function. [ABSTRACT FROM AUTHOR]

The black phosphorus (BP) nanosheets were firstly obtained by the modified lithium ion intercalation method and then functionalized by cetyl-trimethyl ammonium bromide (CTAB). Owing to the electrostatic interactions, the positively charged CTAB was successfully loaded onto the surface of negatively charged exfoliated BP and the BP-CTAB hybrids were finally obtained. It is found that BP-CTAB hybrids exhibits superior promotion effect on fire safety of Polylactic acid (PLA), which can be attributed to its typical layered structure, abundant phosphorus and good dispersion in matrix. Compared with neat PLA, the peak heat release rate (PHRR) of PLA composite with 2 wt% BP-CTAB decreases by 38.8%. Under the same loading of 2 wt%, the PLA/BP-CTAB2.0 shows better flame retardancy than PLA composites with BP or red phosphorus (RP). Moreover, the time to peak heat release rate (T PHRR) of PLA/BP-CTAB2.0 is postponed from 157 to 200 s. Derived from the uniform dispersion of BP-CTAB, the tensile strength of PLA composites are also improved. Meanwhile, the air stability of BP-CTAB in polymer is investigated. It is observed that the A g 1/A g 2 value of BP-CTAB only decreases from 0.57 to 0.54 even after immersion in water for one month, which can be ascribed to the double coating of polymer matrix and CTAB. This work enriches the method of exfoliating BP, and first explores the influence of BP on the flame retardant and mechanical properties of PLA. • Modified lithium ion intercalation method enriches the way of exfoliating BP. • BP-CTAB nanohybrids exhibit significant effect on decrease in PHRR and postponing in T PHRR. • BP-CTAB nanohybrids significantly improve thermal stability of PLA composites. • The air stability of BP-Li nanosheets is enhanced by the double coating of polymer matrix and CTAB. [ABSTRACT FROM AUTHOR]

• Cuprous oxides with sheet morphology (Mn@Cu 2 O-M nanosheets) are rationally designed and successfully prepared. • The prepared Mn@Cu 2 O-M sheets could endow epoxy composites with high flame retardancy and smoke suppression properties. • The mechanism are probably due to the physical barrier effect and catalytic carbonization awarded by Mn@Cu 2 O-M sheets. To date epoxy resins have been extensively used in the field of chemical engineering, aerospace and building materials. Nevertheless, the utilization of flammable epoxy resins has posed a huge threat to lives and properties, which restricted their applications. In this work, manganese-based cuprous oxides two-dimensional nanosheets (Mn@Cu 2 O-M) are rationally designed and successfully prepared to improve the toxic effluent elimination of epoxy resin. The fire safety properties of the prepared Mn@Cu 2 O-M based nanocomposites improved the heat release rate (<35 %) and total heat release (<40 %) compared to the control epoxy. Moreover, the production of smoke and toxic volatiles of the composites with Mn@Cu 2 O-M nanosheets is significantly reduced. The mechanism investigations indicate that the improved flame retardancy and toxic effluent elimination of epoxy composites are attributed to the physical barrier effect and catalytic carbonization awarded by Mn@Cu 2 O-M nanosheets during burning. This work provides a promising strategy to develop eco-friendly, efficient and fire-safe polymers by both physical barrier effect and catalytic carbonization. [ABSTRACT FROM AUTHOR]

• BP nanosheets and MCNTs were combinated via stable phosphorus carbon bonds. • EP/BP-MCNTs exhibits low PHRR, THR, SPR, TSR, FGI and smoke toxicity. • BP-MCNTs possessed naao-barrier, synergistic charring and radicals trapping effect. • MCNTs bonding and EP matrix wrapping improve the air-stable of EP/BP-MCNTs. As a rising star of two-dimensional material, black phosphorus (BP) has attracted tremendous attention in applications of photovoltaics, transistors and batteries due to its unique characteristics. Inspiring, we developed a simple strategy to fabricate BP-MCNTs as highly promising inorganic phosphorus-based flame retardant. After incorporation 2 wt% BP-MCNTs11(the mass ratio of BP:MCNTs=1:1) nanohybrid, the peak of heat release rate and total heat release of EP nanocomposites reduced by 55.81% and 41.17% at a phosphorus content of only 1 wt%, and the comprehensive index FGI for evaluating the flame retardant of materials decreased from 17.35 to 6.97. In addition, the typical flammable volatile are suppressed significantly, and the first stage of carbon monoxide release is disappeared. The improvement of fire safety and inhibition of smoke toxicity could be attributed to the the synergistic effects of nano-barrier, catalytic charring and radicals trapping of BP-MCNTs nanohybrid. More importantly, BP hybrid with MCNTs and wrapped in EP matrix which formed effective isolation protection against the ambient degradation. Raman spectra and SEM results confirmed that EP/BP-MCNTs performed enhanced ambient stability than EP/BP-BS nanocomposites after three months. This study demonstrates its great potential for preparation of air-stable BP based nanocomposites with enhanced fire safety. [ABSTRACT FROM AUTHOR]